The present invention generally relates to paper towel dispensers and, more particularly, to a non-touch paper towel dispenser for dispensing a web of material from a roll.
Dispensers for toweling have primarily been designed to dispense a continuous length of web material, folded paper towels, or rolls of paper towels. Continuous towels are generally made of a reusable material and form a towel loop outside of the dispenser cabinet for the consumer to use. Folded towels are paper towels which are precut and folded into various configurations to be individually dispensed for use. Roll towels are continuous rolls of paper toweling which are wound around a central core and which are, upon dispensing, separated into and delivered as individual lengths of material.
Continuous web dispensers, such as those disclosed in U.S. Pat. No. 2,930,663 to Weiss and U.S. Pat. No. 3,858,951 to Rasmussen, require the user to pull on the loop of exposed toweling in order to cause a length of clean toweling to be dispensed and the exposed soiled toweling to be correspondingly taken up within the dispenser. Although economical, the continuous exposure of the soiled toweling is deemed unsightly and, therefore, unacceptable to many consumers when compared to the many available alternatives. Further, the exposure and possible reuse of soiled toweling may present additional health hazards and sanitation concerns which should be avoided.
The use of interfolded paper towels or C-fold paper towels eliminates the potential health risks associated with continuous web toweling. For instance, dispensers for folded paper towels, such as disclosed in U.S. Pat. No. 3,269,592 to Slye et al., allow a user to dispense the towels by pulling on the exposed end of each new individual towel. These dispensers are also easy to refill with folded towels. However, a number of the folded towels will sometimes drop out of the lower opening of the dispenser when only the exposed towel is pulled, especially when the stack of towels in the dispenser is small. This can result in a significant waste of paper towels. Accordingly, folded towels are not as economical as other kinds of alternative dispensers.
Roll towels are cheaper to manufacture and produce less waste than folded towels. Roll towels also eliminate the potential health and sanitation problems associated with continuous web toweling systems. Dispensers for roll towels may include a lever, crank, or other user-activated mechanism for dispensing a length of towel, and a blade for severing the length of towel from the remaining roll. However, as can be appreciated, manual contact with a dispensing lever or the like raises health concerns for the user. To alleviate these health concerns, dispensers, such as U.S. Pat. No. 4,712,461 to Rasmussen, eliminate contact with any part of the dispenser, and instead rely upon the user directly pulling the paper towel out of the dispenser. As a result, the paper towel must be provided with sufficient strength to effect rotation of the feed roller and actuation of the blade without premature tearing. Paper possessing the requisite strength to operate the dispenser is limited in the amount of softness and absorbency which can be provided to the paper towels.
Dispensers for roll towels have also been electrically powered. As shown in U.S. Pat. No. 5,452,832 to Niada, a light sensitive device is used to detect the presence of a user""s hand in front of the dispenser and advance the toweling for a predetermined length of time. The dispensed length of paper towel is then separated from the continuous web by pulling the paper against a serrated cutting member. While the feed roller is powered, the cutting action still requires the paper to possess a certain minimum strength and generally produces a rough, unsightly cut.
U.S. Pat. No. 4,738,176 to Cassia discloses an electrically powered dispenser which also includes a reciprocating cutter to produce an individual towel from the continuous web of paper. While this arrangement enables the use of softer and more absorbent paper, the dispenser requires a substantial amount of energy to drive the feed mechanism and the reciprocating cutter. Accordingly, the batteries must be replaced much more frequently. Moreover, the system is more complex and costly with its use of one-way clutches.
Also, in some electrically powered dispensers, such as U.S. Pat. No. 4,796,825 to Hawkins, the paper will continually dispense while a hand or other object is placed in front of the sensor. Hence, the dispenser is subject to easy abuse and waste of paper. Moreover, some dispensers are subject to dispensing paper by the general proximity of a person irrespective of whether a paper towel is needed. In an effort to avoid abuses, some dispensers, such as U.S. Pat. No. 4,666,099 to Hoffman, have incorporated a waiting period where the dispenser will not operate for a brief time after each use. However, the need to wait can be frustrating to users under some circumstances.
The present invention is directed to an electrically powered dispenser which overcomes the disadvantages of the prior art.
In one aspect of the present invention, the dispenser facilitates the dispensing of a roll of paper with spaced apart transverse lines of tearing (e.g. perforation lines) for easily separating individual sheets from the continuous roll without cutting. As a result, paper with a high degree of softness and absorbency can be used without the high energy demands required by a reciprocating cutter.
In another aspect of the invention, the dispenser senses the leading edge of the continuous web of paper material to initiate a control device which controls the length of each segment of paper. In this way, the dispenser can always place the transverse tearing line at the proper position in relation to the discharge opening for each dispensed sheet, irrespective of variations of the spacing for the tearing lines within a tolerance range.
In another aspect of the invention, the dispenser includes a sensor for sensing the presence of a sheet which has been dispensed, but not removed, in order to prevent the dispenser from dispensing any more sheets until the previous sheet has been tom off. In this way, abuse of the dispenser and waste of the paper material can be minimized without requiring the use of a waiting period wherein the dispenser will not operate. Accordingly, the dispenser is always ready for use.